One of the tendencies of improving the overall efficiency of traditional volumetric displacement internal combustion engines has been the replacement of the reciprocating pistons of such engines by rotary pistons capable of converting the energy content of the expanding high pressure combustion gases into a direct rotary movement of a driving shaft. The rotary piston engine known as the Wankel engine has been developed furthest in this field, but has not managed to supplant the reciprocating engine due to problems with e.g., sealing materials. Other attempts have been aiming at the development of rotary engines in which a rotor is driven by at least one jet stream of expanding gases which exert a tangential pressure on the circumference of the rotor whereby a part of the energy content of the expanding gas is converted into a driving torque acting on said rotor. Examples of engines of the kind concerned are turbines, especially gas turbines that have found wide-spread application in certain well defined areas. Mainly from literature, designs of internal combustion rotary engines have become known in which a rotor is driven by a continuous series of impulses of expanding combustion gases.
A known prior art device disclosed in U.S. Pat. No. 4,590,761 granted to Zeftner, comprises spaced combustion chambers with recesses therebetween that are arranged around the outer circumference of a rotor. Each recess serves as an expansion chamber for a jet of gas produced by combustion in an associated combustion chamber. A stator has at its inner circumference, retractable reaction members which are movable into the recesses to be acted on by the gas jet so as to create forces acting in opposite sense on the rotor and stator and thus cause the rotor to rotate. This known device seems to be too elaborate since it comprises a large number of cam-controlled movable component parts, and since fuel combustion is performed in open chambers of throttled discharge openings only, the thermal efficiency may also be not sufficiently high for the engine to be viable of practical application.
Another device of the type concerned is disclosed in the published German patent specification DE 1 601 577 A2. The device disclosed herein comprises two equidistantly spaced combustion chambers arranged in a stator along its circumference. Combustion gases generated in these combustion chambers are discharged, at pre-determined intervals into a generally snake-shaped expansion duct which is confined by curved wall partitions of chambers certain parts of which being arranged in both, a rotor of the engine and in said stator. When the engine is supposed to be in operation, said chambers become connected with each other in sequence so that multiple and subsequent expansions of the combustion gaseswould exert alternating active and reactive tangential driving impulses onto the rotor. The expanded combustion gases are finally vented via a duct through the stator in the ambient atmosphere. Considerations given to the disclosed device allow for the conclusion that the device would hardly be capable of practical operation at least in the sense of supplying a driving torque that could be utilised at viable efficiency. The generally snake-shaped expansion duct seems to be too long and too voluminous. In such an expansion duct a permanent counter pressure of substantially constant level may be generated. During the relatively long periods between the successive combustion impulses in the chambers the combustion gases present in said duct may come to a quasi-stagnation. The rate of flow of the gas through said expansion duct is expected to be substantially low because said too long intervals and the relatively large volume of the expansion duct allow for a low velocity, slow release of the expanded combustion gases in the ambient atmosphere. Between the actively and/or reactively driven wall partitions of the rotor chambers long wall sections are present that are, in view of torque generation, at least entirely inactive if not of retroactive effect.
Another example for such an engine is disclosed in the German patent publication DE 1 476 913 A1. The device disclosed herein is, in principle, a multi-stage turbine comprising a rotor provided, in spaced arrangement, with spaced chambers having tangential openings along the circumference of the rotor. When in operation, impulses of a high pressure gas jet are introduced tangentially into said chambers. The impulses exert active and reactive driving forces onto the rotor both upon their entry and also later, during their multi-stage expansion from the chambers. The rotor of the known device is designed and shaped as a hollow cylindrical body having radially directed spokes, and the chambers are arranged in an outer circumferential ring part of the cylindrical body. As an alternative, the same publication discloses the possibility of generating the high pressure gas impulses, at least within the first expansion stage of the turbine, by arranging and operating internal combustion chambers in the rotor. Following the first stage of their expansion, the combustion gases are introduced, via suitable but relatively long conduits, into subsequent stages of the turbine for repeated expansions. Combustion of fuel introduced in the combustion chambers would be performed at constant volume, and the expanding gases would exert, at least during their first stage of expansion, impulses of reactive driving torque on the circumference of the rotor. Due to the relatively long paths of flow for the expanding gases between the subsequent expansion stages and to multiple bends arranged therein, this hybrid solution seems to be hardly efficient enough and thus, capable of replacing the well known reciprocating engines.
The published German patent application DE 3826533 A1 discloses an internal combustion rotary engine having a rotor provided with a plurality of recesses adapted to receive a gas jet of expanding high pressure combustion gases discharged ftom a combustion chamber arranged stationary and in sealed relationship to a pheripheral section of the rotor. When in operation, i.e. the rotor of the engine rotating relative to the combustion chamber, the recesses of the rotor are facing, temporarily and in sequence, the discharge outlet of the combustion chamber. The rotor is kept in continuous rotational motion by the kinetic energy of the jets of the expanding high pressure combustion gases being transferred to the rotor by and during their passage through, and further expansion in the recesses of the rotor. The rotor of the internal combustion rotary engine disclosed in DE 3826533 A1 is designed and shaped as a substantially solid body of rotation, and apart from a brief indication of the heat content of the expanded combustion gases being further utilised by a heat exchanger, no information is disclosed on how the spent combustion gases are released after their expansion.
It is accordingly one object of the present invention to provide an internal combustion rotary engine, especially an engine operating on the principle of a rotary engine driven by a continuous series of tangential impulses exerted onto a rotor by expanding combustion gases of high energy content, the basic design of which would allow for the provision of engines different in size and thus, in performance by using and aligning by simple assembling, different numbers of pre-manufactured, identical component parts. More particularly, the present invention seeks to provide an internal combustion rotary engine that operates with a minimum of losses of energy at high thermal and mechanical efficiency. A further and related object of the present invention is to provide an engine of hitherto not experienced low fuel consumption, the engine being capable of operating with different types of fuel, particularly of liquefied or gaseous hydrogen, in a problem-free manner. Still another object of the invention is to provide a rotary engine that could replace with considerable advantages, the traditional reciprocating internal combustion engines in every field of application. Yet another object of the invention is to provide a method for operating the engine according to the invention in a manner friendly to environment, by producing, if at all, a very low proportion of noxious constituents in its exhaust gases.
It has been recognised that the above and complex objectives can only be realised by providing an engine of the rotary type in which principles and physical effects known, at least in part, such as avoiding reciprocating component parts; using and utilising a rotor of high product of inertia for storing, at least for certain periods of operation, kinetic energy; burning a completely combustible fuel mixture in heat insulated spaces so that adiabatic combustion is performed, allowing and utilising fuel combustion by detonation whereby higher combustion rates and pressures can be achieved, are asserted simultaneously.